Early studies on this question showed that for simple model systems an increasing strain leads to a destabilization of the local packing and results in a strain activated, instead or thermally activated, stress relaxation [1]}, a picture that was elaborated by Falk and Langer who introduced the notion of shear transformation zones (STZ) [2]}. Many subsequent studies have related these STZ and the plastic events (PE) to structural quantities or a high local entropy, indicating that this concept is useful [3]}, [4]}, [5]}, [6]}, [7]}.
